Britain's premier said Thursday he is "sorry" for believing former Cabinet Minister Peter Mandelson's "lies" and appointing him ambassador to the US as pressure continues to build on him after admitting he knew of Mandelson's ties with convicted sex offender Jeffrey Epstein.

"I want to say this: I am sorry. Sorry for what was done to you. Sorry that so many people with power failed you," Keir Starmer told a news conference in East Sussex.

The prime minister said the victims of Epstein, who died in 2109, "have lived with trauma that most of us can barely comprehend, and they've had to relive it again and again."

"Sorry for having believed Mandelson's lies and appointed him, and sorry that even now you're forced to watch this story unfold in public once again," he noted.

Starmer noted that they will not shrug their shoulders, and they will not allow the powerful to treat justice as optional.

"We will uphold the integrity of public life, and we will do everything within our power and in the interests of justice," he added.

"To ensure accountability is delivered. That is what the public expects. That is what the victims deserve, and it is what I will do," said the prime minister.

Starmer says he understands lawmakers' 'anger and frustration'

Asked whether he would stand in a race to be leader should lawmakers decide they wanted a contest, Starmer, without directly replying to the question, said he was elected in 2024 and that he still wants to achieve the promises made in the election.

On the appointment of Mandelson, he said: "I think we need to look at the security vetting because it now transpires that what was being said was not true, and had I known then what I know now, I'd never have appointed him in the first place."

In response to another question about his thoughts after some Labour Party lawmakers expressed that his position is "untenable," Starmer replied he understands their "anger and frustration."

He added: "I'm angry and frustrated like them because nobody wants to see these deceits in public life."

Starmer's remarks came amid growing pressure on him after acknowledging he was aware of former Cabinet Minister Peter Mandelson’s ongoing friendship with late convicted sex offender Jeffrey Epstein when he appointed him last year as the ambassador to the US.

Mandelson was appointed as the British ambassador to the US on Feb. 10 last year but then he was sacked by Starmer on Sept. 11 after emails revealed that Mandelson sent messages of support to Epstein even as the financier was facing jail time for sex offenses in 2008.

Police launch criminal probe

UK police announced Tuesday that they have launched a criminal investigation into Mandelson following claims that he leaked government emails to Epstein.

The move came after the British government on Tuesday referred material to the police after an initial review of Mandelson’s emails to Epstein.

Emails released Friday in the US revealed that Mandelson forwarded internal government information to Epstein while serving as business secretary in 2009.

Mandelson also stepped down from the House of Lords on Wednesday amid ongoing pressure over his links to Epstein.

The latest release of files also prompted Mandelson to resign on Sunday from the Labour Party.

The US Justice Department recently released more than 3 million pages, 2,000 videos and 180,000 images related to Epstein under the Epstein Files Transparency Act, which was signed into law last November.

The materials include photos, grand jury transcripts, and investigative records, though many pages remain heavily redacted. Epstein survivors and victims’ relatives say the release falls short of what the law requires, and omitted much vital information.

Epstein was found dead by suicide in a New York City jail in 2019 while awaiting trial on federal sex trafficking charges involving underage girls.